JSC Design and Procedural Standards

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JSCͲ08080Ͳ2JSCDesignandProceduralStandardsAbstract Thisdocumentcontainsdesignandproceduralrequirementsforhumanspaceflightequipmentbasedon lessonslearnedandbestpractices. Therequirementscapturedinthisdocumentareappropriatefortheacquisition,design,development, test,evaluation,operations,andsustainingengineeringofanyhumanspaceflightprogram,project, spacecraft,system,orenditem. InordertomakethedocumentavailabletoNASA&NASAcontractoremployeesoutsidethe JSCCommunity,thedocumentneedstobepostedtotheNASAStandardsandTechnical AssistanceResourceTool(START)website:https://standards.nasa.gov/documents/jsc

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JSC Design and Procedural

Standards

Engineering Directorate

January 2015

National Aeronautics and Space Administration

Lyndon B. Johnson Space Center Houston, Texas

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1. PREFACE

This document contains design and procedural requirements for human spaceflight equipment based on lessons learned and best practices.

The design and procedural requirements are located in Section 5 of this manual and are identified according to the applicable discipline or category, with letter codes as follows:

G General

E Electrical

F Fluids

M/P Materials and Processes

M/S Mechanical and Structural

P Pyrotechnics

This document is controlled by the JSC Engineering Directorate (EA) Configuration Control Board (CCB).

2. CHANGE

LOG

Revision Date Originator Description of Changes

Basic January 2015

EA5 /

Russell Yates / 281-483-0996

Renumbered document from JSC-STD-8080 to JSC-0JSC-STD-8080-2.

Reformatted requirements.

Deleted key word index, signature block, and historical changes.

Added applicable documents, requirement guidelines, and reference documents.

Rewrote Preface and Introduction.

Improved consistency of numbering and capitalization.

Corrected superscripts / subscripts.

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Added “None.” to Remarks if none. Deleted superseding comments.

G-5: Replaced JSC 49774 reference with NASA-STD-6016.

G-11: Replaced NASA FAR Supplement text with reference.

G-14: Updated FED-STD-595A reference to current revision.

G-22: Reverted to 2005 revision of

requirement, changed “until installed in an assembly” to “throughout their lifecycle,” added JSC references to Remarks section.

G-29: Updated NPR 8705.2 reference to current revision.

G-37: Deleted reference to NASA-STD-3000.

G-39: Updated lightning protection standard references to current revisions.

E-1: Updated NASA-STD-3000 reference to NASA-STD-3001.

E-7: Updated MIL-PRF-39003/10B reference to MIL-PRF-39003/10D w/Amendment 1.

E-13: Updated symbols from uA to PA. E-14: Deleted JSC 49774 reference.

E-20: Removed IEEE C62.38 from list of acceptable test methods.

E-24: Replaced MIL-C-17 reference with MIL-DTL-17, and MIL-W-22759 with SAE AS22759.

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F-27: Updated requirement for de-ionized water lesson learned.

MP-9: Updated JPG 1700.1 reference to JPR 1700.1.

MP-11: Updated pressure vessel standard references to current revisions.

MP-13: Updated pressure vessel standard references to current revisions, and

updated JSC-STD-1710 reference to JPR 1710.13.

MS-4: Deleted reference to NASA-STD-3000.

MS-5: Replaced JSC 49774 references with NASA-STD-5020, NASA-STD-6016, and MSFC-STD-557; added requirement that sole locking feature not rely on preload; changed NASA-STD-3000 reference to NASA-STD-3001.

MS-7: Added reference to NASA-STD-5018.

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3.

MP-14 [Canceled] ... 77 MP-15 [Canceled] ... 77 MP-16 [Canceled] ... 77 MP-17 [Canceled] ... 77 MP-18 [Canceled] ... 77 MP-19 [Canceled] ... 77 MP-20 [Canceled] ... 77 MP-21 [Canceled] ... 77 MP-22 [Canceled] ... 77 MP-23 [Canceled] ... 77 MP-24 [Canceled] ... 77

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MP-25 [Canceled] ... 77

MP-26 [Canceled] ... 77

5.5 MECHANICAL AND STRUCTURAL ... 77

MS-1 Equipment Containers – Design for Rapid Spacecraft Decompression ... 77

MS-2 Alignment, Adjustment, and Rigging of Mechanical Systems ... 77

MS-3 [Reclassified as E-25] ... 78

MS-4 Crew Hatches ... 78

MS-5 Threaded Fasteners ... 80

MS-6 [Canceled] ... 82

MS-7 Windows and Glass Structure ... 82

MS-8 Penetration of Inhabited Spacecraft Compartments ... 83

MS-9 Positive Indication of Status for Mechanisms ... 83

MS-10 [Canceled] ... 83

MS-11 Meteoroid and Orbital Debris Protection Levels for Structures ... 83

MS-12 Spacecraft Recovery Hoist Loops ... 85

MS-13 [Canceled] ... 86

MS-14 Structural Analysis ... 86

MS-15 Fluid Systems – Method of Joining Metallics ... 86

MS-16 Pressure Vessels – Negative Pressure Damage ... 87

5.6 PYROTECHNICS ... 88

P-1 Pyrotechnic Devices – Arming and Disarming... 88

P-2 Pyrotechnic Devices Preflight Verification Tests ... 88

P-3 [Canceled] ... 89

P-4 [Canceled] ... 89

P-5 Pyrotechnic Devices – Identification Requirements ... 89

P-6 Protection of Electrical Circuitry for the NASA Standard Initiator ... 90

P-7 [Canceled] ... 90

APPENDIX A REQUIREMENT GUIDELINES ... 91

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4. INTRODUCTION

4.1 PURPOSE

This document contains design and procedural requirements for human spaceflight equipment based on lessons learned and best practices.

4.2 BACKGROUND

JSC originally published its design and procedural requirements as bulletins circa 1964. In 1971, these bulletins were combined into a single document, JSCM 8080. Since then, JSC has, as needed, issued minor updates to the document, with major revisions occurring in 1991 and 2005. Through the years, the document has undergone several formatting and document number changes (e.g., JSCM 8080, JPR 8080.5, JSC-STD-8080).

4.3 APPLICABILITY

These requirements are appropriate for the acquisition, design, development, test, evaluation, operations, and sustaining engineering of any human spaceflight program, project, spacecraft, system, or end item.

The requirements may be imposed via directive, specification, or agreement.

The requirements may be imposed individually (by referring to individual requirement numbers) or wholly (by referring to the document number). If the requirements are imposed wholly, it is appropriate to assess the applicability of individual requirements (e.g., via an applicability matrix).

4.4 AUTHORITY

JPD 8080.2, JSC Design and Procedural Standards for Human Space Flight Equipment.

4.5 APPLICABLE DOCUMENTS

The latest version of these documents apply unless otherwise specified. The

documents only apply when the referencing requirement applies (see Section 4.3), and only to the extent specified in the referencing requirement. The referencing

requirements for each applicable document are listed in parenthesis following the document name. Documents are grouped as follows and listed alphabetically by document number within each group: law, NASA directives, NASA standards, non-NASA government standards, and other standards.

JPR 1710.13, Design, Inspection, and Certification of Ground-Based Pressure Vessels and Pressurized Systems (MP-13)

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MSFC-STD-557, Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications (MS-5)

NASA-STD-5001, Structural Design and Test Factors of Safety for Spaceflight Hardware (MS-14)

NASA-STD-5020, Requirements for Threaded Fastening Systems in Spaceflight Hardware (MS-5)

NASA-STD-6016, Standard Materials and Processes Requirements for Spacecraft (MP-1, MS-5)

NASA-STD-8739.4, Crimping, Interconnecting Cables, Harnesses, and Wiring (E-14)

SSP 30423, Space Station Approved Electrical, Electronic, and Electromechanical (EEE) Parts List (E-24)

DD Form 250, Material Inspection and Receiving Report (G-14)

DD Form 1149, Requisition and Invoice/Shipping Document (G-14)

FAA AC 20-136, Aircraft Electrical and Electronic System Lightning Protection (G-39)

FED-STD-595, Colors Used in Government Procurement (G-14)

MIL-DTL-17, Cables, Radio Frequency, Flexible and Semirigid (E-24)

MIL-PRF-39003/10D w/Amendment 1, Capacitors, Fixed, Electrolytic (Solid Electrolyte), Tantalum, (Polarized, Sintered Slug), Established Reliability, Styles CSS13 and CSS33 (High Reliability Applications) (E-7)

ANSI/NEMA WC 27500, Standard for Aerospace and Industrial Electrical Cable (E-24) AIAA S-080-1998, Space Systems – Metallic Pressure Vessels, Pressurized Structures, and Pressure Components (MP-13)

AIAA S-081A-2006, Space Systems – Composite Overwrapped Pressure Vessels (COPVs) (MP-13)

ASME Boiler & Pressure Vessel Code (MP-13)

ASTM Manual 36, Safe Use of Oxygen and Oxygen Systems: Handbook for Design, Operation, and Maintenance (F-1, F-16, F-19)

NAS412, Foreign Object Damage / Foreign Object Debris (FOD) Prevention (G-5)

SAE ARP5412, Aircraft Lightning Environment and Related Test Waveforms (G-39)

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SAE ARP5415, User’s Manual for Certification of Aircraft Electrical/Electronic Systems for the Indirect Effects of Lighting (G-39)

SAE ARP5577, Aircraft Lightning Direct Effects Certification (G-39)

SAE AS22759, Wire, Electrical, Fluoropolymer-Insulated, Copper or Copper Alloy (E-24)

4.6 CANCELATION

JSC-STD-8080, JSC Design and Procedural Standards

5. DESIGN AND PROCEDURAL STANDARDS

5.1 GENERAL

G-1 Equipment Accessibility for Maintenance

STATEMENT OF STANDARD

Systems, subsystems, equipment, and components shall be designed with features that contribute to the ease and rapidity of maintenance.

Equipment expected to require servicing, replacement, or maintenance shall be

designed to be accessible without removal of other equipment, wire bundles, and fluid lines. This should include accessibility during ground operations (horizontal and vertical) as well as on orbit.

Electrical connections and cable installations shall be designed with sufficient flexibility, length, and protection to permit disconnection and reconnection without damage to wiring or connectors.

Panel-mounted displays and controls that are inside the habitable areas shall be capable of being totally maintained from the habitable area. Each display and control installation shall be designed to permit removal and replacement without disturbing the validity and integrity of other components or subsystems.

REMARKS

The version updated in October 2004 modifies the text to align better with longer-term maintenance activities encountered on longer duration space missions such as the International Space Station (ISS) or exploration missions.

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G-2 Separation of Redundant Systems

Redundant systems, redundant subsystems, and redundant major elements of subsystems (such as assemblies, panels, power supplies, tanks, controls, and associated interconnecting wiring and fluid lines) shall be separated or protected to ensure that an unexpected event which damages one is not likely to prevent the other from performing the functions.

Electrical wiring of redundant systems, redundant subsystems, or redundant major elements of subsystems shall not be routed in the same wire bundle or through the same connector with wiring of the other redundant system, subsystem, or subsystem element.

This standard is not applicable to redundant components or piece parts mounted in common housings within redundant systems, subsystems, or subsystem elements.

This standard does not apply to redundant explosive charges that are located adjacent to each other in order to sever structural members at a given point or along a given line. However, the electrical wiring of redundant systems and routing shall apply.

REMARKS

For purposes of this standard, "redundancy" is defined as the ability to perform a function by more than one means.

This recommended separation for electrical wiring also applies to fluid lines.

G-3 Electrical and Fluid Systems Checkout Provisions

Electrical and fluid systems and subsystems shall be designed to permit checkout tests and shall include provisions (e.g., test points) that permit these checkout tests to be conducted without disconnecting any tubing, mated flight couplings, or any other mated flight connectors.

Test points shall allow checkout of the system without loss of integrity (e.g., loss of pressure, leakage, loss of continuity, etc.).

REMARKS

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G-4 Protection from Debris – Electrical & Mechanical Systems

Electrical and mechanical systems shall be shielded in such a way that encounters with debris or foreign material do not cause a malfunction. Acceptable methods include, but are not limited to, the following:

1. Design and fabricate electrical circuitry to prevent the establishment of unwanted current paths from such debris.

2. Provide critical electrical items with debris-proof covers, suitable containers, housings, potting, or conformal coatings.

3. Provide critical mechanical systems with debris-proof covers, shrouds, or containers that protect the entire system prior to use, or that prevent debris from entering into critical areas of the mechanism where the debris could cause binding, jamming, or seizing.

4. Incorporate filters, strainers, traps, screens, or other devices in moving-fluid

components of electrical or mechanical systems to trap debris in a manner that will eliminate it as a threat to critical mechanical or electrical components. In systems where flow reversal may occur, install such devices on both sides of critical

components. Make sure all such devices are able to be cleaned in-flight and/or are able to be replaced as part of the maintenance program.

REMARKS

Refer to G-5 for prevention of debris.

Crew cabin module ventilation fans are low pressure-drop devices with small clearances between blades and duct to maximize efficiency and minimize power consumption. Under microgravity conditions ventilation systems are particularly prone to blockage due to particulates. International Space Station ventilation systems

suffered up to 80% reduction in flow due to the entrainment of clusters of particulate or fibrous debris in the ventilation systems. This debris penetrated through a protective screen with .02-inch diameter hole size, but then combined to block internal flow paths with .125-inch diameter. Because simple screens have been shown to be ineffective in long duration protection of ventilation systems in microgravity, depth filters should be used to protect ventilation systems from particulate fouling for long-duration missions. A similar phenomenon can occur in liquid media systems where particulates chemically combine downstream of the filter to produce larger than screen-size debris clumps. These systems should be assessed for the use of depth filters or more effective chemical filters.

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G-5 Prevention of Debris – Electrical & Mechanical Systems

A Foreign Object Debris (FOD) prevention program shall be established for all ground operations of mechanical and electrical systems of flight hardware including the design, development, manufacturing, assembly, repair, processing, testing, maintenance, operation, and check out of the equipment to ensure the highest practical level of cleanliness.

The FOD prevention program shall conform to NAS412, Foreign Object Damage / Foreign Object Debris (FOD) Prevention.

REMARKS

Refer to G-4 for protection from FOD.

NAS412 is available through NASA Technical Standards Program at Marshall Space Flight Center.

Refer to NASA-STD-6016, Standard Materials and Processes Requirements for Spacecraft, for selection of materials to prevent growth of biological contaminants.

G-6 [Canceled] G-7 [Canceled]

G-8 Design for Redundancy Verification

Spacecraft systems, subsystems, and equipment shall be designed to permit verification of redundant functions or operational modes any time the system, subsystem, or equipment requires testing prior to launch or during the mission.

REMARKS

This standard is not to be interpreted to require verification of redundancy every time the system, subsystem, or equipment is tested but merely to require that the

systems/subsystems/equipment be designed in a manner to allow redundancy

verification if it is deemed necessary. Verification of redundancy may occur at any time from acceptance testing through launch processing, mission operations, and post flight.

G-9 Shatterable Material – Exclusion

Shatterable materials shall not be used in the habitable compartment unless positive protection is provided to prevent fragments from entering the cabin environment.

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Photographic, optoelectronic, and television lenses are exempt from this standard when in use, but they shall be protected by suitable covers when not in use.

This standard is also applicable to nonflight hardware or ground support equipment (GSE), including wiring and tubing that is carried on or used in the habitable

compartment subsequent to start of equipment installation, at the contractor's facility or in a Government facility.

REMARKS

None.

G-10 Time/Cycle Critical Part Control

1. Spacecraft components which are time-critical and/or cycle-critical or which have limited storage life shall be subject to the following controls:

2. Each time-critical or limited-life assembly, subassembly, component, and spare shall be clearly and indelibly marked with a serial number.

3. Appropriate documentation shall accompany all time-critical and limited-life items and shall include the date of manufacture of the item and of its most time-critical component. Realistic life limits shall be assigned and documented for each item and shall be suitably altered as new data and new evidence are obtained.

4. Status records shall be maintained on all such items after installation in the spacecraft. Operating-time logs shall be maintained for all items having limited operating lives. Components shall have sufficient life remaining to adequately support mission requirements.

5. Special storage requirements shall be carefully defined and strictly observed.

6. A time-age-life cycle database shall be maintained for verification (and notification) of time-age-life component status.

REMARKS

This requirement may be satisfied by the inventory management subsystem of the onboard data management system.

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G-11 Procurement Document Identification for Human Spaceflight Items

Purchase requests (PRs), requests for proposal (RFPs), purchase orders (POs), credit card purchases, contracts, and subcontracts for items procured for use in human spaceflight shall be submitted with the statement shown below.

The information shall be printed, stamped, or added in boldface type.

FOR USE IN HUMAN SPACEFLIGHT, MATERIALS, MANUFACTURING, AND WORKMANSHIP OF HIGHEST QUALITY STANDARDS ARE ESSENTIAL TO ASTRONAUT SAFETY.

IF YOU ARE ABLE TO SUPPLY THE DESIRED ITEMS WITH A QUALITY WHICH IS HIGHER THAN THAT OF THE ITEMS SPECIFIED OR PROPOSED, YOU ARE REQUESTED TO BRING THIS FACT TO THE IMMEDIATE

ATTENTION OF THE PURCHASER.

Procedures shall assure that new PRs, RFPs, POs, contracts, and subcontracts issued by prime contractors and their subcontractors down to the lowest tier include this

information. Present contracts and subcontracts involving such hardware shall be amended at the earliest possible date to require the prime contractor or subcontractor to establish such procedures in all actions covering new procurement.

REMARKS

See 48 C.F.R. § 1852.246-73, NASA Federal Acquisition Regulations Supplement, Human Space Flight Item (1997).

G-12 Application of Previous Qualification Test Data

When certifying an item for a new application, use of qualification test data obtained during a previous certification shall meet the following conditions prior to use:

1. There is no change in design and specifications from the original item certified including operating limits, weight, dimensions, materials, performance and tolerance, reliability, and quality.

2. The configuration (part number and dash number) previously tested is identical to the configuration proposed for the new application.

3. Manufacturing/Fabrication methods and process have not changed and are certified

4. Previous environmental test conditions are greater than or equal to the

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5. Previous functional/performance test results are greater than or equal to the

accuracy, input-output, sensitivity, and other performance/operational characteristics required for the new application.

6. The previous test configuration is documented and is considered an adequate methodology/technology to provide test results for the new application.

7. Previous test equipment tolerances and data resolution are documented.

8. Inspection methods, inspection points, and acceptance test procedures are greater than or equal to the rigor of previous methodologies.

9. Previous operating environments, exposure duration, cycling, and usage are greater than or equal to the operations concept required for the new application.

10. Previous failures have been evaluated for impact to the validity of test and analysis data

REMARKS

Flight Certification of any item involves evaluation of verification data to determine if customer requirements have been met. When some of that data is already available from a prior flight certification program, and the appropriate technical evaluation determines that the data can be used to support a new certification program, it is cost effective to use existing data instead of performing additional testing. Previous failures and waivers must be reconsidered or resubmitted for approval by the authorizing organization. Environmental testing typically refers to vibration, thermal, thermal vacuum, radiation, loads, and electromagnetics.

G-13 [Canceled]

G-14 Classification of Flight and Non-Flight Equipment

The status of flight equipment and nonflight equipment (equipment which is not suitable for use in flight but which could be accidentally substituted for flight articles) shall be identified and classified as follows:

CLASS I Equipment acceptable for flight use. Identification shall be in accordance with drawings and specifications.

CLASS II Equipment acceptable for use in ground tests or training in a hazardous environment. The nameplate or a label adjacent to the nameplate shall be conspicuously marked "CLASS II,

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CLASS III Equipment acceptable for nonhazardous training or display

purposes. This equipment shall be conspicuously identified by red (or orange) stripes alternating with a contrasting base color or painted solid red. Red paint no. 28913 as specified by FED-STD-595, Colors Used in Government Procurement, is the preferred color. An alternative to the paint method of identification is a red (or orange) striped nameplate or label marked "CLASS III, NOT FOR FLIGHT" applied to the equipment. The identification shall be visible when the equipment is installed.

In addition, equipment not readily identifiable as nonflight equipment, as well as nonflight equipment hidden from view in a major module, shall have a red (or orange) serialized streamer attached to, or in the immediate vicinity of the installation. The streamer shall be of a size and material compatible with the environment under which it will be used. Streamers are to be traceable to the major module which identifies and controls the item. A record of nonflight equipment and, if appropriate, associated

streamer serial numbers shall accompany each major module upon formal transfer (i.e., DD250/1149) from one organization to another.

Appropriate instructions shall be printed on each streamer. Streamers shall be numbered and accounted for prior to launch.

The color coding requirements of this standard do not apply to explosive devices.

REMARKS

Nonflight equipment or hardware must be identified to preclude possible use during a flight mission.

Hazardous environment is defined as a chamber environment (such as vacuum, high temperature, low temperature, and oxygen-rich atmosphere) or any other environmental condition that could subject the user of the equipment to a hazard of any kind.

G-15 Resolution of Flight Equipment Failures/Anomalies Prior to Launch

Where flight or flight-like equipment has failed or otherwise exhibited anomalous performance or intermittent operation, launch-to-orbit of identical or like equipment, either as part of the flight vehicle or as a replacement, shall not be permitted unless one of the following occurs:

1. It is verified that the basic deficiency which caused the failure or anomalous performance is not present in the flight equipment or its replacement.

2. The basic deficiency has been counteracted by changes in operational procedures to a degree that eliminates it as an unacceptable risk to the success of the mission or the safety of the crew.

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3. The basic deficiency does not present an unacceptable risk to the success of the mission and safety of the crew.

Do not use equipment that exhibits or has exhibited intermittent malfunctions, failures, or anomalies for flight until the malfunction, failure, or anomaly has been corrected or resolved to the satisfaction of the Flight Readiness Review Board.

REMARKS

This standard supports the current philosophy that all failures or anomalous performance must be resolved before launch.

Where the cause of an inconsistency remains unresolved, equipment is unreliable.

G-16 Operational Limits on Temperature-Controlled Equipment

For spacecraft equipment where the operating temperature is normally controlled by heating or cooling equipment and the temperature is monitored in ground test and flight, the test program and/or appropriate analyses shall define the following:

1. The maximum and minimum temperatures expected in normal operations

2. The maximum and minimum temperatures (including duration and temperature rate of change, as appropriate) at which equipment may be expected to:

a. Fail to meet specified performance until temperature is restored to normal range.

b. Be permanently rendered inoperative.

For critical components, automatic safing with manual override only shall be used.

Information used to satisfy requirements 1 and 2 above shall be provided in operational constraints documentation.

REMARKS

Knowing the maximum and minimum operating limits of spacecraft equipment is essential for flight and mission management. This information needs to be readily available for real time decision-making.

Item #1:

This information is needed for equipment characterization and could be used for recognizing a thermal malfunction within the spacecraft equipment.

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Item #2

This information provides guidance to NASA in an unlikely, off-nominal mission scenario that normal operating temperatures may need to be exceeded due to malfunction(s) either external or internal to the equipment. In such a scenario it may become necessary to operate equipment beyond the qualification limits and mission manager's need to know how far the equipment can be pushed and reasonably expect that the equipment can be turned off and subsequently reactivated to support the safe return of the crew. The ultimate purpose of this information is to enable flight and mission management to make the best decisions possible in an off-nominal situation to maximize the probability of safely returning the crew.

Relevant information used to form the guidelines may include data or analysis from other program or manufacturer development (from Department of Defense (DoD) to Commerical of the Shelf (COTS)), data from operational programs due to unplanned thermal conditions, similar hardware data (document similarities and contrasts, e.g. non-screened parts data), sub-part data, bench testing that was not previously documented in reports, inadvertent test conditions, etc.

The desired outcome is a set of useful temperature and duration guidelines for the deliverable units at the lowest cost. Therefore, deriving the guidelines from the best available information is preferred and supplemental high-cost testing must be approved by the Program. Engineering judgment should also be applied and documented as appropriate in meeting this requirement.

G-17 Separate Stock for Spaceflight Parts and Materials

Assemblies, parts, and materials procured or designated specifically for use in space shall be:

• positively identified

• stored in controlled access areas

• physically separated from nonflight parts and materials to avoid mixing.

REMARKS

This standard is to prevent nonstandard, nonspaceflight, nonsegregated stock from being unintentionally used in space or in the fabrication of spaceflight equipment.

For purposes of this standard, the term "controlled access area" is defined as: stock areas or areas of rooms which are separated from nonflight stock areas or rooms by fences, walls, or other physical separations and which have access control to ensure the following:

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1. Access by authorized personnel only

2. Proper parts and materials storage, maintenance, and withdrawal

3. Compliance with applicable quality assurance directives

G-18 Safety Precautions – Test and Operating Procedures

Procedures developed for testing and operating spaceflight equipment or ground support equipment shall clearly indicate any step which, if not correctly followed, would result in injury to personnel, damage to a system or equipment, or an environmental impact.

The cover sheet of the procedure shall indicate if the test or operation is hazardous.

REMARKS

A warning statement, preceded by the word WARNING in upper case letters, is commonly used to emphasize any instructions which, if not correctly followed, would result in injury to personnel, damage to a system or equipment, or an environmental impact. The statement usually indicates the reason for the warning.

G-19 Special Processes – Identification of Drawings

Manufacturing, assembly, or installation drawings for spacecraft, space flight equipment, experiments, and ground support equipment shall identify all special processes required to manufacture, assemble, and install the equipment.

Process specifications shall be referenced, or the processes shall be specified in detail on the respective drawings.

All referenced specifications not normally available shall be submitted upon request.

REMARKS

The requirements of this standard are in addition to other requirements of the drawing system used. The preferred method of documenting the special processes is to release separate process specifications and to make reference to the specifications on the drawings.

Examples of special processes are cleaning, potting, etching, wire splicing, soldering, welding, brazing, and bonding.

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G-20 Spacecraft Equipment – Protection from Liquids During Ground Operations

Equipment sensitive to moisture and located where it is subject to liquid leaks during ground operations shall be identified in the design documentation. This documentation shall also include:

• The rationale for positioning the equipment in that location. • A plan for implementing protection of this equipment.

REMARKS

Major damage to spacecraft and serious delay of programs can result from small, easily correctable leaks that would be of minor significance except for the effect of the leakage on exposed equipment. Experience has shown that fluid system leaks are particularly prevalent during initial ground testing of new spacecraft.

Sources of moisture and liquid leaks may include systems fluids, water condensation, fluid from GSE or facilities, and natural phenomena.

Protection from damage by leakage may include one or more of these methods:

1. Designing the equipment to be insensitive to the liquid leakage

2. Designing the plumbing or equipment containing the liquid to locate couplings, vents, service points, and other items where leakage from them could not reach the sensitive equipment

3. Providing ground support equipment or devices to protect the sensitive equipment from leakage during ground operation

4. Providing proper insulation to prevent condensate from forming and subsequently falling on the equipment

G-21 Spacecraft Equipment – Moisture Protection

Spacecraft equipment within a pressurized compartment shall be designed so that performance of the equipment will not be degraded by humidity or moisture droplets in the spacecraft atmosphere or by condensation of moisture from the spacecraft

atmosphere.

REMARKS

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G-22 Product Identification

Parts used in flight hardware shall be identified by physical part marking or container marking per requirements defined on the applicable drawing.

Hardware drawings shall include identification processes necessary to control parts throughout their lifecycle.

REMARKS

Identification requirements, such as user control number, nomenclature, serialization, lot number, date code, values, tolerances, sizes, and polarization may also be

necessary for specific parts. Marking systems may include human readable and/ or machine readable codes. Physical marking with alphanumeric characters, direct part marking, bar coding, and combinations of the three methods are example solutions.

For purposes of this standard, a part is defined as one piece or two or more pieces of material joined together that are not normally subject to disassembly without destruction of design use.

The detailed methods for numbering and marking parts should be provided in documentation, such as specifications and drawing system manuals.

This standard applies to all parts including electronic, electrical, electromechanical, mechanical, and machined parts.

JSC parts management and traceability requirements and processes are defined in the following documents:

• JPD 8500.3, Serial and Lot Numbers for Certain Items of Government-Furnished Equipment

• JPR 1281.8, Product Identification and Traceability • JPR 8500.4, Engineering Drawing System Manual.

G-23 Pressure Garment Wiring – Ignition of Materials by Electrical Current

Electrical current entering a crew member's pressure garment shall be limited to a level that will not ignite or damage materials that would contact damaged wiring within the garment under the worst combination of short-circuit current and environment.

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Energy storage or conversion devices capable of producing short-circuit current of a magnitude and discharge rate sufficient to ignite materials shall not be located inside pressure garments, unless:

1. adequate current limiting is provided, or

2. there is no contact between potentially damaged wires and the material in question

REMARKS

In this standard, "no contact" is defined as no electrically conductive path.

The fire hazard associated with inclusion of communications and bioinstrumentation wiring in the oxygen-rich environment of pressure garments necessitates the analysis and selection of suitable materials to minimize the potential flammability hazard. It is necessary to confirm the compatibility of the materials and electrical currents under failure conditions in the planned oxygen environment.

Current limiting may be required to assure values below the threshold level for ignition of materials caused by arcing or heating from high-resistance heat sources. An

alternative to current limiting is strategic materials placement to ensure that flammable materials, that are demonstrated to ignite at the use conditions, are prevented from contacting potentially damaged electrical wiring or componentry.

Selection of materials with suitable flammability characteristics is constrained by other requirements, such as flexibility, bulk, weight, and comfort of the crew.

G-24 Protecting Flight Equipment from Support Equipment

Ground support equipment (GSE), airborne support equipment (ASE), facility

equipment, or test equipment used in ground or flight operations shall be equipped with protective devices to preserve safe operation margins of the flight equipment.

REMARKS

GSE or ASE, as a result of misuse or malfunction, has the potential for causing

irreparable damage to spacecraft flight systems if the GSE or ASE does not incorporate design features for protecting against such eventualities.

All GSE and ASE designs should be evaluated from the standpoints of inadvertent operator error and hardware (component) malfunction to ensure that protective features are adequate to safeguard spacecraft subsystems. Consideration should be given to the need for not only static overload protection (such as pressure relief, electrical fuses, etc.) but also protection from such elements as dynamic or transient conditions (e.g., electronic filters, accumulators) or contaminants (e.g., contaminant filters).

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G-25 Thermal Design and Analysis

Hardware shall be designed to function in the full range of the thermal environment to which it will be exposed.

Thermal analyses shall be performed for nominal and worst-case conditions for all temperature-sensitive components and structures.

Worst hot and cold cases shall be analyzed using realistic combinations of thermal parameters which produce the worst-case conditions.

REMARKS

Example: A solar constant with 3 percent seasonal variation will be used. Other heat flux impacts, solar absorptances, emittances, conductances, etc. will be varied to include measurement uncertainties, variations in application of coatings, and

degradation. Boundary temperatures and heater voltages will be varied over the ranges expected.

Thermal analysis includes both transient and steady state.

This standard incorporates SSP 30213 no. G-25.

G-26 Internally-Generated Radiation

Laser sources sufficiently powerful to be a hazard shall be positioned to preclude the possibility of looking directly at the source.

Sources emitting electromagnetic wavelengths between x-ray and visible light,

sufficiently strong to pose a hazard, shall be positioned to preclude crew exposure or touch.

Hazard distance shall be marked.

REMARKS

None.

G-27 Fire Control

The primary means of fire control shall be the selection of materials that are

nonflammable or nonpropagating in their use configuration. Materials flammability control is addressed in MP-1, Materials and Processes Control.

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The capability for fire detection and suppression shall be provided.

The material used to extinguish fires shall be nontoxic to humans and shall be capable of being easily cleaned up after it is used.

REMARKS

Fire, particularly in a space vehicle, can be catastrophic. Special precautions are necessary, more so than on earth, because countermeasures must be self-contained within the space vehicle.

In microgravity conditions, fires that are not actively fed with oxygen will self-extinguish. One fire control strategy is to eliminate ventilation, remove electrical power, evacuate personnel, and allow the fire to self-extinguish.

Fire-resistant storage should be provided for hardware that is controlled for flammability by stowage when not in use.

G-28 Sealing – Solid Propellant Rocket Motors

On completion of final inspection following manufacture, each solid propellant rocket motor shall be sealed and pressurized to prevent damage due to entry of moisture or foreign material.

The pressurant shall be dry N2 gas.

The pressure applied shall be sufficient to ensure against entry of contaminants under any anticipated storage conditions.

The seal shall be designed to withstand internal pressure corresponding to the maximum anticipated storage temperature with an adequate safety factor or shall include a relief device.

The seal shall be installed such that it can be expelled during normal rocket ignition without damage to the nozzle. If no other provisions can be made to inspect the grain, access shall be provided through the seal.

REMARKS

The seal may contain provisions for relief of pressure, pressurizing, and pressure gauge installation as necessary.

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G-29 Reentry Propulsion Subsystem In-Flight Test

Crewed spacecraft which use a separate propulsion subsystem for reentry attitude control shall include means for testing this subsystem before jettisoning the last of any other attitude control systems which could be used to position the spacecraft in a reentry attitude.

REMARKS

Control circuitry and attitude cues should be developed to enable the crew to test the reentry propulsion subsystem of the reentry module before abandoning an operating attitude control subsystem.

This standard is not applicable for spacecraft without a separate propulsion subsystem for reentry attitude control. For such cases, refer to NPR 8705.2, Human-Rating Requirements and Guidelines for Space Flight Systems, Section 3.2, System Safety Requirements.

This standard does not preclude the need for redundant reentry attitude control systems.

G-30 [Canceled]

G-31 Detachable Crew – Operated Actuating Tools

Where possible, actuating devices shall be made an integral part of the equipment to be operated.

Detachable actuating tools, such as handles, pins, and ratchets, shall not be permitted in applications where tool nonavailability could compromise crew safety or primary mission objectives.

Where tools are allowed for system controls, provisions shall be made whereby the position of the control is readily apparent to the responsible crew member without the tool in place.

REMARKS

Detachable tools are generally undesirable for all applications in the crew compartment under zero-gravity conditions, but such devices may be used if a significant advantage in operation, weight reduction, or volume reduction is assured and if their application does not conflict with the constraints outlined above.

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G-32 [Canceled] G-33 [Canceled] G-34 [Canceled] G-35 [Canceled] G-36 [Canceled]

G-37 Verification of External Visibility

Visibility verification for crewed spacecraft shall include tests, simulations, or analyses to verify visibility during all anticipated phases and environmental conditions of the planned mission and contingencies.

Simulations shall include mockups or high-fidelity computer simulation to ensure the view (picture) seen by the crew during each phase of the simulated mission will be comparable to that which will be seen in flight.

REMARKS

Whenever possible, visibility verification tests should incorporate actual flight hardware.

The external visibility may be provided using windows, external cameras, or alternative capability.

During previous crewed spaceflight missions, visibility problems have occurred.

Deposits have covered windows. Visibility has been restricted by parts of the spacecraft during certain mission phases. Light gathering properties of some optical instruments have not been satisfactory. Reflections and parallax have caused difficulty. Moisture has condensed between inner and outer panes of windows. Fingerprints and smear marks have compromised optical surfaces.

Factors affecting satisfactory visibility include but are not limited to:

1. Visibility and field-of-view requirements during each phase of the intended mission and for all anticipated contingencies.

2. Protection or preventive measures to avoid unsatisfactory degradation of visibility due to buildup of solid or liquid deposits on all window surfaces, viewing ports, or other optical devices.

3. Scene displays that will be required for simulators and training to ensure satisfactory crew training.

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5. Parallax.

6. Possible angular reflections, particularly from rays of the sun.

7. Optical surface coatings and treatments used to control optical properties and the sensitivity of the treated surfaces to human contact and environmental exposure.

8. Thermal and vacuum conditions to which the viewing device will be subjected.

9. Obstruction of critical view by parts of the spacecraft itself.

High fidelity computer simulation capabilities may enable alternative methods for

verifying visibility rather than using mockups. The computer simulations are flexible for trying out multiple window/camera configurations, whereas mockups are less flexible.

G-38 Pressurization or Repressurization – Preventing Ingress of Undesirable Elements

In the design of pressurization, repressurization, and ventilation systems for habitable areas, provisions shall be made to prevent ingress of undesirable elements.

This standard applies to spacecraft which have habitable areas pressurized at less than atmospheric pressure during normal mission and which must enter the earth's

atmosphere or other atmospheres with pressures different from the spacecraft's normal operational pressure for habitable areas.

REMARKS

During atmospheric entry and landing, undesirable elements such as vented

propellants, heat shield fumes, and water may be ingested into habitable areas unless design or procedural precautions are taken.

This standard in not intended to apply to airlock ingress and egress pressurization and depressurization procedures.

G-39 Lightning Protection Design

Lightning protection shall be designed into spacecraft which will operate in Earth's atmosphere such that, in the event of a lightning strike, flight hardware will not be damaged or affected to the extent that mission success, crew, or ground personnel safety is compromised.

Verification of adequate protection shall be accomplished using both test and analysis based on technical detail contained in:

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• SAE ARP5412, Aircraft Lightning Environment and Related Test Waveforms • FAA AC 20-136, Aircraft Electrical and Electronic System Lightning Protection • SAE ARP5414, Aircraft Lightning Zoning

• SAE ARP5415, User’s Manual for Certification of Aircraft Electrical/Electronic Systems for the Indirect Effects of Lighting

• SAE ARP5577, Aircraft Lightning Direct Effects Certification

REMARKS

This standard has not been evaluated for its applicability to other atmospheres.

G-40 Radioactive Luminescent Devices

When radioactive material is to be used, such as radioactive luminescent devices, the following requirements shall be met:

1. Each proposed use of radioactive material shall be approved by the JSC Radiation Safety Committee.

2. A minimum amount of radioactive material shall be used consistent with the requirements.

3. Radioactive materials shall be completely sealed or encapsulated in substances having low damage potential from the inherent radiation.

4. Installation within or on the vehicle shall be such that it is unlikely that the seal of the radioactive material will be damaged because of ground or space environment, accidents, or mishandling. Installation in the habitable volume of a manned vehicle and/or in a location for potential contact with any crew member during extravehicular activity (EVA), intravehicular activity (IVA), ingress, or egress shall be protected against damage to eliminate the possibility of particle ingestion, inhalation, and/or skin contact by the crew.

5. The component bearing the radioactive substance shall be designed for replacement with no damage to the seal of the radioactive substance.

6. Each item containing radioactive material shall be permanently marked in a manner approved by the JSC Radiation Safety Committee.

REMARKS

A byproduct material license issued by the U.S. Nuclear Regulatory Commission authorizes JSC to use radioactive components on spacecraft. This license, issued

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pursuant to Title 10, Code of Federal Regulations, requires that each use of radioactive material be reviewed and approved by the JSC Radiation Safety Committee for

compliance with NASA and JSC health and safety issuances, the Code of Federal Regulations, and other applicable statutes.

The type and degree of protection referred to in paragraph 4 will be dependent upon the amount of luminescent material and the design and location of the device.

G-41 [Canceled] G-42 [Canceled] G-43 [Canceled]

G-44 Attitude Control Authority

Spacecraft automatic attitude control circuitry shall be designed so that the crew can assume manual attitude control at all times.

REMARKS

This revision increases the scope of the standard to require capability for manual takeover of the automatic attitude control circuitry during all phases of the mission.

G-45 Solid Propellant Rocket Motors

Solid propellant rocket motors shall be designed with the capability to ignite without a seal, or with a nozzle seal failure, up to the highest altitude and maximum elapsed time at which ignition is required.

REMARKS

Nozzle covers (seals) are required to protect the grain from the environments but the motor should be capable of being lit when necessary even in the event of a seal failure.

REFERENCES:

See G-28, Sealing – Solid Propellant Rocket Motors.

G-46 Separation Sensing System – Structural Deformation

Separation sensing systems designed to detect separation of stages or modules of space vehicles shall not inadvertently actuate separation sensors due to structural

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deformations or vibrations less severe than those associated with the structural failure of the vehicle.

Separation sensing systems that are designed to initiate subsequent steps in a

sequence of events shall be designed so that the failure or actuation of a single sensor will not initiate the sequence of events.

Separation sensing systems shall be designed not to initiate a sequence of events unrelated to space vehicle separation.

REMARKS

Separation sensors have erroneously given signals of spacecraft module separation because of structural deformation. On an uncrewed flight, high aerodynamic and vibrational loads caused structural deformation that resulted in an inadvertent firing of the launch escape tower.

Structural deformation must be considered during the installation design to locate separation sensors where relative motion of the structural elements is not excessive and where inspection of the sensor can be accomplished. The sensors should be selected to require actuation travel substantially greater than the maximum deformation anticipated between the structural elements at the point of installation.

G-47 Gyroscopes – Verification of Operational Status

Guidance, Navigation and Control subsystems utilizing gyroscopes shall provide continuous outputs during operation to verify that gyroscopes are operating within specified limits.

Gyroscopes shall be capable of providing operational readiness status prior to use.

Failures shall be detected within a timeframe that allows for corrective action prior to negative consequences resulting from the failure.

REMARKS

Optimum spacecraft operation and safety are dependent upon properly functioning gyroscopes. Failure detection and redundancy is desirable to mitigate the effects of gyroscope failures or off nominal operation.

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G-48 Onboard Experiments – Required Preinstallation Checklist

Furnish analytical proof or conduct tests to demonstrate that proposed onboard experiments shall not impair the safety or effectiveness of the astronaut or jeopardize the functioning of spacecraft equipment under worst case conditions.

Examples include:

• Releasing solids, liquids, or gases.

• Producing temperature extremes or releasing thermal or ionizing radiation. • Emitting electromagnetic radiation.

• Degrading external and internal visibility. • Degrading internal auditory environment. • Impeding crew ingress and egress.

• Jeopardizing the integrity of the spacesuit.

• Interfering with the operation of EVA or IVA controls.

• Jeopardizing the integrity of the spacecraft power system by transients or short circuits.

• Producing damage as a result of cabin decompression or recompression at maximum possible rate.

• Producing damage through loss of structural integrity during any spacecraft operation including land or water landings at maximum design conditions. • Producing damage as a result of stored energy release.

REMARKS

Instances have occurred where materials that were prohibited from use in the spacecraft environment were planned for experimental use.

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G-49 [Canceled]

G-50 Direct Procurement of Parts

The initiator of purchase requests and other applicable procurement documents for parts used in a spacecraft, space flight equipment, experiments, and ground support equipment shall specify on the procurement document that procurement must be made directly from the manufacturer or from distributors who can furnish certification of the following conditions:

1. The item was actually produced or assembled by the designated manufacturer.

2. The item conforms to the manufacturer’s current standards of performance and quality for items of the specified designation.

3. The distributor can furnish any traceability records or documentation required by the PR for materials control, process control, and limited life tracking. Traceability requires a configuration control system that includes drawing version control, fabrication records, and hardware serialization or lot tracking.

REMARKS

There have been cases of procurement of obsolete, out of tolerance, and improperly stored parts when lot control and serialization were not specified.

G-51 Flight Hardware – Restriction on Use for Training

Hardware and equipment that is scheduled as primary or spare equipment for flight shall not be used for training, unless all of the following conditions are met:

1. Training use is strictly limited to the prime and backup flight crews or a designated delegate.

2. Adequate crew familiarity with the characteristics of the actual flight equipment cannot be obtained from fabrication and use of flight-like training hardware or training models.

3. A record of all training use is documented per controlled hardware documentation requirements.

4. The equipment will subsequently be subjected to inspection and preinstallation acceptance tests prior to flight.

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5. After such training use, the life remaining on all limited-life items will be adequate for completion of the mission.

REMARKS

October 2004 text modified to address crew availability during long-duration missions such as the International Space Station or exploration missions and hardware obtained specifically for training purposes.

G-52 Reuse of Flight Equipment

Flight equipment that has been previously used in flight may be reused in crewed flight if the following minimum conditions have been met:

1. Appropriate refurbishment, inspection, and testing have been accomplished between flights.

2. Any elements not replaced will be within all shelf-life limits, operational time or cycle life limits, and environmental (e.g., vibration) life limits at the end of the mission.

3. No evidence exists that the unit has been stressed beyond specification limits during previous use.

REMARKS

None.

G-53 Reverification

After successful completion of some or all of the verification program, changes may occur that dictate the need for reverification assessment. Such changes may include changes in design configuration, material, manufacturing or procurement sources, operating environments, etc. Baseline characterization data such as chemical and physical properties of materials including fluids as well as impurity composition and levels shall be collected during initial qualification such that any follow-on changes may be assessed relative to possible or anticipated impacts to equipment performance. When such changes as those identified below occur, a reverification assessment shall be performed to determine the need to repeat previously completed verification

activities.

Qualification Reverification: If changes occur in any of the following, an assessment to determine the need to repeat any or all of previously completed qualification activities shall be performed and documented:

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1. Design configuration or manufacturing process changes (e.g., bonding, soldering, welding, installation torques of fasteners, etc.)

2. Changes in fluids or lubricants; either in their specifications; procurement source, processing; transportation, or storage, or handling conditions.

3. Changes in materials or parts; either in their specifications; procurement source; manufacturer; or processing.

4. Changes to equipment, part, fluid, or lubricant manufacturer or manufacturing facility.

5. Inspection, test, mission change, or other data indicates that a more severe environment or operating condition exists than that to which the equipment was originally qualified.

6. Changes to flight software coding or capability.

When repeat of some or all of previously completed qualification activities is conducted due to such changes, a reverification report shall be written to formally document the reason for the reverification, justification for the degree of reverification performed, and the results of the reverification activity.

Acceptance reverification: If changes occur in any of the following, an assessment to determine the need to repeat any or all of previously completed acceptance activities shall be performed and documented:

1. Any change consistent with the above changes identified for qualification reverification.

2. A previously mated and verified interface has been demated.

3. Any modification, repair, replacement, or rework occurs on the equipment.

4. The equipment is subject to drift or degradation during transportation, storage, or handling.

REMARKS

This standard replaces information previously covered for qualification fluids in F-23 (1991).

G-54 Automatic Shutdown of Launch Vehicle Engine(s)

Automatic shutdown of launch vehicle engine(s) procedures/design shall maximize crew survival probability as part of the overall system.

JSC Design and Procedural Standards